Synchrorotor.



Patented Dec. 3, 1912.

2 SHEETS-SHEET 1.

INVENTOR Wrmzsszs E. G. THOMAS.

SYNGHROROTOR.

APPLICATION IILED DOT. 23, 1909.

1,045,909. Patnted Dec. 3, 1912.

2 SHEETS-SHEET 2.

Wrmssscs |N\/ENTOR iinwnan e. 'rnomas, or BROOKLYN, NEW YORK."

' srncnnonoroa.

\ Specification of Letters Patent.

Patented Dec. 3, 1912.

Application filed October 23, 1909. Serial No. 524,284.

To all wfiom it mag concern: V

Be it known that I, EDWARD G. Tumors, of Brooklyn, county of Kings, State of New York, have invented and produced certain new and useful Improvements in-Synchrorotors, of which the followin is a specification, reference being had to t e accompanyinildrawings, which form a art thereof.

' y invention is'intende to provide'an improved apparatus by which the move ments of a mechanical device, such as a r0- tating shaft, may be controlled by and made synchronous with the periodic movements of another device,'for example, a pendulum or another rotatingshaft,apparatus of this cliaracter'being useful in *many ways, such as in connection with synchronous teleg-' raphy, clocks, astronomical instruments,

steam engine governors, and the like. For convenience the former device and its operating mechanism-may be termed the governed device, and the latter the controlling device.

The controlling device may consist of any assemblage of parts having a periodic rotary or reciprocating motion, such as a clock pendulum, while the, overned de'vicemay be described in a genera way as compr1s1ng:-'

a rotating member which is driven by power from an outside source at a speed of rotation greater than the speed which the system is designed to impart to the above apparatus; a

yielding driving connectionbetween the above apparatus and the rotating member;

andmea'ns for controlling the number of revolutions of the rotating: member by a niechanical or electrical connection between, the controlling device and the governed device so that the number ofrevolutions of the rotating member in a given time will be equal to or a multiple or integral part of the totalnumber of revolutions or movements of the controlling devicein the same time.

The specific form to which the greater part of the following description applies is that inwhich the controlling and governed devices are electricallyconnected, the controlling device in this case consistingof any a paratus included inan electric circuit a apted tolmake and break said circuit at periodic intervals. p

My invention is illustrated in the accompanyingdi'awings in which' Figure 1 is a planview partly in section of a preferred form of the mechanism employed open and close an 'electric'circuit.

, as a governed device, showing also in side elevation a, periodic c'rcuit closing apparatus which miiy be emfiyed as the controlling device. ig. 2 is an end view of the apparatus shown in plan in Fig. 1, viewed from the left side of said figure, and showing the parts in one position; Fig. 3 is a view similar to Fig. 2,'but showing the parts in another position. Fig. 4 is an end view of a. similar apparatus, except that in this case there is a. mechanical connection between the controlling and governed devicesr Fig. 5 is a plan view'of a portion of the apparatus, illustrating a modification of the adjusting devices and the application of the synchrorotor to the production of musical tones.

Referringto Figs. 1, 2 and 3 of. the drawings, I have shown at the bottom of Fig. 1 a form of circuit-closer which may serve as the controlling device, consisting of a rotating shaft 2, driven by clockwork or othensuitable means at a rate corresponding to the periodic interval to be synchronized at the governed device and carrying a commutator wires 5 and 6 are connected to said spring 4 and to the. 'ournal of shaft respectively and lead there om to the governed evice, a battery 7 or other source of electric energy, being included, in the circuit. The rotation of the shaft 2'will, evidently result in breaking the electric circuit whenever the spring 4 .is in contact with the insulating segment 3, while at other times the circuit will be corn- 1 pleted by the contact of said spring with the metallic portion of the commutator. This circuit controller is entirely diagrammatical in character, is not a part of this invention, and maybe replaced by any other form of mechanism which will serve to periodically The device employed at the receiving Station comprises, according to the construction shown, a shaft 8 suitably journaled in supports" 9, secured to a base 10. Upon the shaft is-mounted a driving device consisting of a? friction clutch comprising a continuously driven and loosely-journaled pulley,

11, provided with a double faced ring 12,

which may be cast integral with the web of said pulley and makes frictional contact on both its faces. with friction pads or plugs secured to the ends of two spiders '14, and 15. Spider 14 is attached rigidly to shaft 8. Spider 15 is splined to the shaft 8 by means of a key 17 and springpressed toward spider 14 by means such as a spring 18 hearing against a collar 19. The shaft 8 is thus frictionally driven, and its rotation is controlled by means of an electrically operated stop, which preferably consists of an electromagnet 20, the armature 21 of which is connected to a pivoted stop rocker 22, one end of which is located either within or adjacent to the path of some part re- I volvingwith the shaft 8, such as an exten- 31. Bevel gears 32, 33, 34, and 35 and their sion 23 formed on the spider 15, according to the position of said armature. In order to diminish the shock caused by the engagement of the extension 23, with the stop rocker 22, and also to lessen the tendency of such engagement to force the armature 21 away fro-m the magnet, I prefer to provide the engaging end of the stoprocker 22 with a pivoted finger 24, supported by a rubber buffer 25, and to so locate the pivot on which said lever turns that the impact or pressure of the extension 23, upon the finger 24, will be exerted nearly in a linepassing through said pivot, the latter being located just far enough outside of said line to cause the pressure of the extension 23 to exert a lateral thrust upon said lever sufficient to throw it outward when the magnet 20 is deenergized. The same result may be accomplished or contributed to by beveling the end of the finger 24, as shown, the extension 23 being preferably provided with an antifriction roller 26, to serve as the cooperating contact surface when the stop operates.

On' the shaft 8, is loosely mounted a .fly wheel 27, which is connected with and driven by said shaft through the medium of a spring 28, secured at one end to said fly wheel and at the other end to some member carried by the shaft,'such asthe hub of the spider 14. To the fly wheel 27 is connected in any suitable manner the part or mechanism to be synchronized. This mechanism is herein diagrammatically illustratedby.

gear 29, which is rotatively mounted on shaft 8 and is firmly secured to fly wheel 27, gear 30 in engagement therewith, shaft 31 'to which gear 30 is secured, bevel gear 32,

also secured to shaft 31, bevel gears 33 and 34, rotatively mounted in gear 36, bevel gear 35 and commutator 37, rigidly secured together and rotatively mounted on shaft mounting gear 36 constitute a differential gear of which the purpose will be disclosed ater. 5

The operation of the parts above described is as follows: The pulley 11 is driven continuously by suitable means at a speed such that it will perform one complete rotation in an interval somewhat less than that of the periodic impulses received from the controlling device and by reason of its frictional connection with the shaft 8, it will rotate said shaft, together with the fly wheel 27, and the synchronized shaft 31, at its own speed so long as no obstacle to such rotation is interposed by the stop mechanism. The latter can interpose no such obstacle as long as the circuit through the wires 5 and 6 is open-and the magnet is denergized, but whenever said circuit is completed and a current is sent through the magnet, the finger 24 willbe firmly held in the path of the roller 26, and if, while the circuit is closed, said roller is brought by the rotation of the pulley 11 into contact with the finger 24, the further rotation of the shaft 8 will thereby be prevented until the stop lever is released by the breaking of the circuit. As soon as the circuit is broken, the pulley 11 will turn the shaft 8 through another revolution, during which the circuit will again be closed, and since this revolution will be accomplished in a less interval than that elapsing between-the periodic breaks in the circuit, the roller 26 will again come in contact with the finger 24, While the stop lever is held by the magnet 20, whereupon the rotation of the shaft 8 will again be arrested until the circuit is again broken. The breaking of the electric circuit at the periodic intervals is accomplished at the controlling device by the rotating shaft 2 or otherwise, as above described, and hence in this manner the shaft 8 will be prevented from making more than one rotation ineach of the periodic intervals, although the pulley 11 will make some what more than one rotation in each interval.

The rotation of the shaft 8 will, .therefore, be intermittent, and in each of the periodic intervals it will perform a complete rotation which will occupy less than the entire interval, and it will also have a period of rest equal to the difference between the periodic interval and the interval required for one rotation of the pulley 11. Since the speed of the shaft when in motion is slightly greater than the average speed imparted to the fly wheel and synchronized mechanism, it is evident that the tendency of the shaft while in motion is, during a certain part of its motion, to accelerate the speed of the fly wheel, and while at rest to retard it, since while the shaft is in motion it will carry forward the end of the spring rest, the end attached to the fly wheel will travel forward and impart a twist to the spring in the opposite direction from that previously given. By a suitable relation between the inertia of the fly wheel andsynchronized mechanism and the strength of the spring, the variations in speed of this mechanism may be made so small as to be negligible, and the rotation will be substantially uniform and will correspond in num' ber of turns in a given, time to that of the shaft 8. The synchronized shaft 31 and fly wheel will thusbe given a substantially uniform speed of rotation at a rate bearing a definite relation to the periodicity of the circuit closer at the controlling device.

The spider may be provided with any number of stops, so that its rotation will be interrupted more than once in a revolution,

'. and itsspeed may be made in this way to erned device.

bear any ratio less than unity to the periodicity of the breaking of the circuit.

As a safety device to prevent the fly wheel from running farther ahead of the spider 14 than is desirable should. the periodiccircuit breaker fail to open the circuit at the proper moment, there \is installed in the circuit a circuit breaker consisting of contact-strips 6- .and 7 mounted on an arm 22' on rocker 22. strip 7 is extended to engage a projection (preferably of insulating material) 27 on fly wheel 27, when the armature 21 is in contact with magnet 20. Projection 27 has an. inclined face and if the fly wheel 27 runs ahead of spider 14 sufliciently to permit it to engage the end of strip 7 it will push it away from strip 6' thus opening the circuitand effecting the release of stop 24. Normally the stop will be released before projection 27 can engage strip 7 and the strip 7 is then carried out of the path of. projection 27 bythe retreat of rocker 22 and attached arm 22.

In order to compensate for variations in the work to be done in maintaining in rotation the device to be synchronized which may. arise through variations in the pressure of brushes-on a commutator or similar causes, -I arrange a friction brake, as is shown in Fig. 2 to press with an'adjustable pressure on the rim of the fly wheel. A lever 96, pivotally securedto base 10, carries a friction plug 97. Lever 96 is pressed against fiy wheel 27 by ascrew 92 passing through a tapped hole in standard 93 and hearing against a leaf spring 94. By turning the screw in or out the friction of the plug 97 against the face of fly wheel 27 may be varied to increase or diminish the work to be done. Y

1 In Fig. 4 a mechanical connection is arranged between the controlling device here represented by a rotating cam, and the gov- The stop mechanism shown The end of the contact pressed against a cam 43, secured to a rotating shaft 44. Once in each revolution of shaft 44, cam 43 will act to force arm 39 out of engagement withstop roller 26 and thuspermit the rotation of shaft 8 as has previously been described.

In order to provide a means for- Varying the speed of rotation of a governed device, as, for instance, commutator 37 from that corresponding to the periodic rate of the controlling device, I have shown in Fig. 1 the commutator 37 driven from fly wheel 27 through a differential gear. Part 36 of this differential is a gear wheel which engages a pinion 50 secured to a shaft 51 mounted in journals 52; This shaft is splined and upon it is slidably mounted a disk 53. This disk is keyed to shaft 51, and therefore willrotate with it. A fork 54 attached to a rod 55 isarranged to slide disk 53 along shaft 51. A conical drum 56 is rotatably mounted in journals 52 and may be driven by a pulley 57 from any suitable source of power. Drum 56 is in driving contact with disk 53 in all positions of the latter along shaft 51 and obviously will impart to it and through it to gear 36 of the differential a' speed of rotation varying in accordance to the position of disk 53. Every complete rotation of gear 36 will cause two rotations of bevel gear 35 and commutator 37 and if such rotation is accomplished while the synchrorotor is in operation, the rotations of the commutator resulting will be added to or subtracted from the rotations caused by the synchrorotor according to the relative direction of the respective motions.v

The differential gear and the means for driving will also serve for changing the angular position of the commutator in reference to the fly wheel 27, where it is not desired to continuously add to or subtract from its rotations. This'will be effected by turning shaft 51 by hand to the extent de sired. In Fig. 5 another means of adjustment for the differing speeds of differentsynchrorotors is shown. The commutator 60 is secured to shaft 31, which is driven as through gear 30 from the same driving mechanism that is shown in Figs. 1, 2, and 3 and which it is therefore unnecessary to show here. The commutator 60 will rotate at the speed of gear 30 and shaft 31. A brush holder ring 63 of insulating material carries brush holder 62 and brush 61 which bears upon commutator 60. Brush holder 62 is electrically connected with a contact ring 63 on the outside of brush holder ring 64 and a brush 65, mounted on an insulating block 66 on the base 10 ofthe machine makes contact with this contact ring. Brush holder ring 64 is secured to bevel gear 32, forming a part of a differential gear, which consists of bevel gear 32, bevel -gears 33 and34, pivotally mounted in adjusting gear 36, and bevel gear 35. Gears 32, 35, and 36 are loosely journaled onshaft 31, while adjusting gear 36 engages the pinion 50 of a variable speed mechanism identical in character and operation with that previously. de-

scribed. Bevel gear 35 is secured to a worm wheeP 67, which is en aged by a worm 68, secured to shaft 69 WhlCh is journaled in the base 10 and which may be readily turned by hand through an attached head 70. It will be obvious that the brush 61 may be rotated about shaft 31, either by moving adjusting gear 36, through the. variable speed mechanism provided, by moving, gear 35 by turning shaft 69 and its attached worm 68 or by accomplishing both motions at the same time, and thereby the revolutions of commutator 60 in respect to the brush may be diminished or increased by moving the brush in the same or opposite direction to the motion of the commutator.

Contact brush 65, contact ring 63, brush holder 62, brush 61 and any selected bars of the commutator are parts of the signaling circuit which it is the purpose of the machine to maintain. Other brushes, .contact rings and contact brushes may be added where more than one signaling circuit is desired. An an illustration we may assume that all of the bars of the commutator except one are completely insulated. This one is connected to shaft 31 and the frame of the machine is made a part of the signaling circuit containing a suitable source of current. Obviously once in each revolution of the commutator the circuit will be completed through the commutator bar and-brush 61 and an impulse sent into the line. If more than one impulse per revolution is desired it is only necessary to connect other bars with the firstl This adjustment of relative rotational speed between commutator and brushes will .be most desirable in synchronous telegraphy where 1t is desired to keep in step commuta-.

tors or kindred devices at distant points in order to accurately distribute among a number of local circuits at one point, the impulses sent from a similar number of local circuits at another point and transmitted over a single line or by the methods of wireless telegraphy between the two points, as is done in the systems of Delaney, Rowland and others. We will assume that synchrorotors are located at these points and that the controllingdevices are clocks having pendulunis beating seconds and operating circuit breakers once per second. Even with the most accurate clock mechanism exact isochronism cannot be attained and a diiference between the clocks of from one to five beats per day may be expected. As the number of beats of a seconds pendulum per day is 86,400 it will obviously be necessary at one point to add to or subtract from every 86,400 rotations of the commutator resulting from the operation of the synchrorotor a number of rotations equal to the difference between the beats of the two clocks per-day if the clock at the other point is beating exactly seconds. This will be accomplished and the relative rotation of the two commutators in respect to their brushes made synchronous by a suitable arrangement of the differen ial gear and variable speed drive.

An important use of my device is in connection with the production of musical sounds in that class of instruments, such as the choralcelo, wherein steel strings, supported, in connection with a sounding board upon a piano plate, are vibrated by the action of electromagnets, placed in juxtaposition thereto and periodically energized by an interrupted current. In Fig. 5. a piano plate 80, carries a steel string 81, and sounding board 82. String 81 bears at one end on a bridge 83, secured to sounding board 82, and upon a rail 84 at the other, and is stretched between pin 85 and tuning pin 86 in the usual manner. Mounted on a bracket 87 and opposite the string, but not in contact therewith, is a magnet 88. The circuit 89 of this magnet includes contact brush 65, contact ring 63, brush holder 62, brush 61', commutator 60, the frame of the machine, a source of electric current and a circuit breaker 90 operated by a piano key. The commutator 60 in this case consists of nearly equal segments of conducting and insulating materials, all the conducting segments being electrically joined to one another and to the frame of the machine. Now when the key 91 is pressed down and closes circuit breaker 90, a rapidly interrupted current is sent through the magnet 88, which periodically attract-s and releases the string 81. If the periodicity of the interrupted current is the same as the rate of vibration of the string, it is thrown into vibrations sufiicient for producing strong musical tones. As it is found that an extremely small dif-' ference between the periodicity of the current and the rate of vibration of the string is suflicient not only to destroy the desired quality of the-tone produced, but also to very greatly diminish the volume, it is essential that the speed of the commutator 60 shall be uniform and definite.

My device may be modified in many structural respects, and by the substitution of mechanical or electrical equivalents for any of the parts of the mechanism without thereby necessarily altering its essential operation. Such modification will readily oocur to those skilled in mechanic arts and I have not deemed it necessary to illustrate them here. I i

I claim as my invention the following:

1. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, a stop for said rotating member, means for operating said stop, a mechanism to be synchronized, and elastic driving connections between the latter and said rotating member.

2. In a synchronizing apparatus, a governed device comprising a rotating member, a driving pulley, a friction clutch connected to said rotating member and arranged to engage said pulley, a stop for said member, means for operating said stop, a mechanism to be synchronized and elastic driving connections between the latter and said rotating member.

3. I11 a. synchronizing apparatus, the combination of a governed device, comprising a rotating member, driving means therefor, a stop for said rotating member, a mechanism to be synchronized and elastic driving con nections between the latter and said rotating member, with means for periodically releasing said stop.

4. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, elastic driving connections between said rotating member and the mechanism to be synchronized, a stop lever, a cooperating stop member carried by said rotating member and means for operat ing said stop member.

5. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, a stop mechanism for said rotating member, a fly Wheel, mechanism to be synchronized, means for driving said mechanism from said fly wheel, and elastic driving connections between the fly wheel and said rotating member.

6. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, a stop for said rotating member controlled by an electric circuit, a mechanism to be synchronized, and elastic driving connections between the latter and said rotating member.

7. In a synchronizing apparatus, a governed device comprising a rotating member, a driving pulley, a friction clutch connected to said rotating member and arranged to engage said pulley, elastic driving connections between said rotating member and the mechanism to be synchronized, and an electrically controlled stop mechanism for saidv rotating member.

8. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, elastic driving connections between said rotating member and the mechanism to be synchronized, and an electrically controlled stop for said rotating member comprising an electro-magnet, a stop lever connected to the armature thereof, and acooperating stop member carried by said rotating member.

9. In asynchronizing apparatus,- a governed device comprising a rotating member, driving means therefor, an electrically controlled stop mechanism for said rotating member, a flywheel mechanism to be synchronized, means for driving said mech anism from said fly wheel and a spring connection between said rotating member and fly wheel for driving the latter.

10. In a synchronizing apparatus, a governed device comprising a rotating member, a driving pulley, spiders 14 and 15 rotatively secured to said member, a means for pressing them against the pulley, a stop secured to one of said spiders, a pivoted lever adapted to be engaged by said stop, an electro-n'iagnet having its armature connected to said lever, and a spring connection between said rotating member and themechanism to be synchronized.

11. In a synchronizing apparatus, a governed device comprising a rotating member, driving means therefor, a yieldingly supported, stop member, a cooperating stop member carried by the rotating member, a mechanism to be synchronized, and elastic driving connections between the latter and said rotating member.

12. In a synchronizing apparatus, the combination with an electric circuit and means for producing periodic interruptions therein of a governed device comprising a rotating member, driving means therefor, a

stop for said member controlled by the electric circuit, a mechanism to be synchronized, and elastic driving connections between the latter and said rotating member.

13. In a synchronizing apparatus, the combination with an electric circuit and means for producing periodic interruptions therein of a governed device comprising a rotating member, a driving pulley, a friction clutch connected to said rotating member and arranged to engage said pulley, elastic driving connections between said rotating member and the mechanism to be synchronized, and astop for said rotating member controlled by the electric circuit.

14. In a synchronizing apparatus, the combination with an electric circuit and means for producing periodic interruptions therein of a governed device comprising a rotating member, driving means therefor, elastic driving connections between said rotating member and the mechanism to be synchronized, a stop for said rotating member comprising an electro-magnet included in said circuit, a stop lever connected to the armature of the magnet, and a cooperating stop carried by said rotating member.

15. In a synchronizing apparatus, the combination with an electric circuit and means for producing periodic interruptions therein of a governed device comprising a rotating member, driving means therefor, a stop mechanism for said rotating member controlled by the electric circuit, a fly wheel connected with the mechanism to be synchronized, and a spring connection between said rotating member and fly wheel for driving the latter.

16. In a synchrorotor the combination of a governed device comprising a rotating member, driving means therefor, a stop for said rotating member, a mechanism to be synchronized, including two rotating parts and means for varying their relative angu-' lar velocities, elastic driving connections between said rotating member and said mechanism to be synchronized, with means for periodically releasing said stop.

17. In a synchrorotor, the combination with an electric circuit and means for producing periodic interruptions therein of a governed device comprising a rotating member, driving means therefor, a stop for said member controlled by the electric circuit, a mechanism to be synchronized, including two rotating parts and means for varying the relative rotative speed of said parts, and

- elastic driving connections between said rotating member and said mechanism to be synchronized.

18. In a synchrorotor, the combination of a rotatively supported device consisting of two members, a spring of which one end spring through a predetermined are at regularly recurring intervals, with means for adding to or subtracting from the rotations of one of said members.

20. The combination of a rotatively supported member, a spring of which one end is secured to said member, means for producing rotation of the other end of the spring through a predetermined are at regu- 21. In a synchronizing apparatus a governed device comprising a rotating member, driving means therefor, stop mechanism for said rotating member, mechanism to be synchronized, including-a commutator, elastic driving connections between said rotating member and said mechanism to be synchronized, a brush contacting with said commutator and adjusting means for said brush.

22. In a synchronizing apparatus a governed device comprising a rotating member, driving means therefor, stop mechanism for said rotating member, mechanism to be synchronized including a commutator, elastic driving connections between ,said rotating member and said mechanism to be synchronized, a brush rotationally supported and' variable speed mechanism for rotating said brush.

23. In a synchrorotor, the combination of a rotatively supported fly wheel, a spring, of which one end is secured to said fly wheel, and means for producing intermittent rotation of the other end-of said spring through a predetermined are at regularly recurring intervals.

24- In a synchrorotor, the combination of a rotatively supported fly wheel, a spring having one end operatively secured thereto, and means for rotating the other end of the spring through a predetermined are at regularly recurring intervals, said periods of rotation being separated by periods of reose.

p 25. In a synchrorotor, the combination of a rotatively supported fly wheel, a spring having one end operatively secured thereto, mechanism for rotating the other end of the spring through a predetermined arc, the periods of motion being separated by periods of repose, and means for causing the change from repose to motion to occur in equal intervals of time.

EDWARD G. THOMAS.

Witnesses:

CHAS. J. Foes, GEO. R. BEAL. 

